Repair or refurbishment of limited use medical devices

ABSTRACT

A powered medical device includes electronic components on a circuit board embedded within the body of a plug for connecting the device with a control apparatus. The medical device may be repaired or refurbished without the need to access the embedded circuit board through the use of a supplemental circuit board installed into the open end of the plug adjacent the plug pins. The supplemental circuit board may include a variety of electronic components, including fuses or non-volatile memory.

RELATED APPLICATIONS

The application is a divisional application of U.S. patent applicationSer. No. 15/432,985 filed Feb. 15, 2017, now U.S. Pat. No. 10,321,899issued Jun. 18, 2019, which application is a continuation of U.S. patentapplication Ser. No. 14/843,404 filed Sep. 2, 2015, now U.S. Pat. No.9,578,773 issued Feb. 21, 2017.

BACKGROUND

The present invention is directed to powered medical devices. Inparticular, the present invention relates to the repair andrefurbishment of such powered medical devices.

Endoscopy in the medical field allows internal features of the body of apatient to be viewed without the use of traditional, fully invasivesurgery. Endoscopic imaging systems enable a user to view a surgicalsite and endoscopic cutting instruments enable non-invasive surgery atthe site.

Powered medical devices, including electrosurgical instruments, havebeen used together with endoscopy to cut and shape tissue at thesurgical sites to which these instruments are applied. A typicalelectrosurgical instrument has an elongated shaft, sometimes called a“probe,” with a handle at one end and a tip at the opposed end. One typeof electrosurgical instrument available to surgeons is referred to as abipolar electrosurgical instrument. An active electrode is fitted intothe tip of this instrument. The shaft of the bipolar electrosurgicalinstrument functions as the return or reference electrode. A generatorprovides energy to a distal end tip of a probe within the surgical site.In one mode, the probe provides energy at a power level to ablate orotherwise surgically remove tissue. In another instance, energy isprovided to the probe in order to coagulate the tissue at the surgicalsite to minimize bleeding thereat.

Tissue ablation is achieved when a high power electrical signal having asufficiently large voltage is generated by a control console anddirected to an attached probe. Application of the high power signal tothe probe results in a large voltage difference between the twoelectrodes located at the tip of the probe (presuming a bipolar probe).This large voltage difference leads to the formation of an ionizedregion between the two electrodes, establishing a high energy field atthe tip of the probe. Applying the tip of the probe to organic tissueleads to a rapid rise in the internal temperature of the cells making upthe neighboring tissue. This rapid rise in temperature nearinstantaneously causes the intracellular water to boil and the cells toburst and vaporize, a process otherwise known as tissue ablation. Anelectrosurgical “cut” is thus made by the path of disrupted cells thatare ablated by the extremely hot, high energy ionized region maintainedat the tip of the probe. An added benefit of electrosurgical cuts isthat they cause relatively little bleeding, which is the result ofdissipation of heat to the tissue at the margins of the cut thatproduces a zone of coagulation along the cut edge.

In contrast to tissue ablation, the application of a low powerelectrical signal having a relatively low voltage to the activeelectrode located at the tip of the probe results in coagulation.Specifically, the lower voltage difference established between theactive and return electrodes results in a relatively slow heating of thecells, which in turn causes desiccation or dehydration of the tissuewithout causing the cells to burst.

The electrosurgical instruments described above and many other medicaldevices, both therapeutic and diagnostic, are electrically powered andinclude electrically powered control or sensing means. These devices mayhave only a limited useful life before repair or refurbishment isnecessary. The limited lifetime of these devices is determined as theperiod during which the devices can be relied upon to perform well,after which the devices must either be replaced or serviced. Examples oflimited-use therapeutic devices are electrosurgical operatinginstruments such as electrocautery surgical diathermies and hemostaticscalpels, endoscopic devices such as laparoscopic scissors and probes,arthroscopic operating instruments, angioplasty reaming instruments, andultrasonic instruments. Examples of limited-use diagnostic devices arephysiologic sensors, such as those used for the measurement ormonitoring of physiological and biochemical parameters, (i.e. oxygen,glucose, etc.).

Accordingly, methods have been developed for accurately tracking theusage of a limited-use medical device. The ability to track device usageprovides the capability for replacing or refurbishing a device before itfails, a vital consideration where the device is used in criticalmedical applications, such as surgical operations, or monitoringcritically ill patients.

For example, powered medical devices may include a non-volatile memorydevice for tracking and accumulating usage data. In addition, anon-volatile memory device associated with a limited-use medical devicemay be used to automatically set the operational parameters (or otherparametric data) for the limited-use device when the device is connectedto a generator or other power supply, controller or measuring apparatus.

Alternatively, powered medical devices may include other electroniccomponents that identify the medical device and indicate that themedical device has previously been used. For example, medical devicesuse one or more resistors that identify the medical device type when itis attached to a generator and one or more fuses that are selectivelyblown to indicate that the device has been used.

In certain powered medical devices, the non-volatile memory or otherelectronic components may be encapsulated inside a plug of the device.This configuration has several advantages, including compact size andincreased protection for the electronic components. However, thisarrangement also prevents the electronic components from being accessedfor repair or refurbishment without cutting open or otherwise damagingthe plug and destroying its integrity and usefulness.

Accordingly, a need exists for a method that allows repair orrefurbishment of electronic components within the plug of a poweredmedical device without damaging the plug.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other advantages of the invention will become apparentupon reading the following detailed description and upon reference tothe drawings.

FIG. 1 shows a side view of an electrically powered medical device inaccordance with embodiments of the invention.

FIG. 2 shows, partly in section, an embodiment of a detachableelectrical connecting cable for use with an electrically powered medicaldevice.

FIG. 3 shows an exploded view of an embodiment of a plug intended foruse with a powered medical device.

FIG. 4 shows an embodiment of a circuit board in accordance with anembodiment of the present invention.

FIG. 5 shows an alternative embodiment of a plug intended for use with apowered medical device.

FIG. 6 shows a view from a forward end of a plug in accordance with FIG.5.

FIG. 7 shows a plan view of a supplemental circuit board in accordancewith embodiments of the present invention.

FIG. 8 shows a view of a forward end of a plug as illustrated in FIG. 6with a supplemental circuit board installed.

FIG. 9 shows an isometric view of a removal tool in accordance withembodiments of the present invention.

FIG. 10 shows an isometric view of an installation tool in accordancewith embodiments of the present invention.

FIG. 11 shows an embodiment of a removal tool as illustrated in FIG. 9engaging a supplemental circuit board.

FIG. 12 shows an alternative embodiment of a circuit board in accordancewith an embodiment of the present invention.

FIG. 13 shows an alternative embodiment of a circuit board in accordancewith an embodiment of the present invention.

FIG. 14 shows an embodiment of a supplemental circuit board inaccordance with embodiments of the invention.

FIG. 15 shows an isometric view of an alternative embodiment of aninstallation tool in accordance with embodiments of the presentinvention.

FIG. 16 shows an isometric view of an alternative embodiment of aremoval tool in accordance with embodiments of the present invention.

FIG. 17 shows a flow chart of the steps for refurbishing anelectrosurgical instrument for the first time in accordance withembodiments of the present invention.

FIG. 18 shows a flow chart of the steps for refurbishing anelectrosurgical instrument for a second or subsequent time in accordancewith embodiments of the present invention.

While the invention is susceptible to various modifications andalternative forms, specific embodiments have been shown by way ofexample in the drawings and will be described in detail herein. Itshould be understood, however, that the invention is not intended to belimited to the particular forms disclosed. Rather, the invention is tocover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the invention.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Embodiments of the invention are now described in detail. Referring tothe drawings, like numbers indicate like parts throughout the views. Asused in the description herein and throughout the claims, the followingterms take the meanings explicitly associated herein, unless the contextclearly dictates otherwise: the meaning of “a,” “an,” and “the” includesplural reference, the meaning of “in” includes “in” and “on.” Relationalterms such as first and second, top and bottom, forward and rearward,and the like may be used solely to distinguish one entity or action fromanother entity or action without necessarily requiring or implying anyactual such relationship, direction or order between such entities oractions. Also, reference designators shown herein in parenthesisindicate components shown in a figure other than the one in discussion.For example, talking about a device (10) while discussing figure A wouldrefer to an element, 10, that is not shown in figure A but is shown in adifferent figure.

Referring to FIG. 1, an illustrative embodiment of an electricallypowered medical device having electronic components, such as resistors,fuses or non-volatile memory, encapsulated in a connector is described.Device 10 comprises an electrically powered scalpel having handle 11,blade 12, cable 13, and connector 14. Device 10 is merely oneillustration of an electrically powered medical device, and thoseskilled in the art will immediately recognize applicability of thepresent invention to a vast array of electrically powered medicaldevices. Electrical cable 13 terminates at connector 14, which connectsdevice 10 to an external power supply and control apparatus. Electroniccomponents 30 may be disposed within connector 14 of device 10. Thepresent invention may also be practiced with an instrument having handle11, so that the electronic components are disposed within the handle.

FIG. 2 depicts a connecting cable 20, which may be used interchangeablywith a number of compatible medical instruments. Connecting cable 20terminates at each end with electrical connectors 21 and 22. Electroniccomponents 30 may be disposed within either electrical connector 21 or22 to store data or provide other functionality pertaining to use of thecable.

In an embodiment of the invention, a powered medical device includes aplug or connector that attaches and electrically connects the medicaldevice with a generator.

FIG. 3 shows an exploded view of an embodiment of a plug intended foruse with a powered medical device. As illustrated in FIG. 3, the plug 40connects with a cable 35. The cable may include one or more wire strandssurrounded by a shielding material. The cable connects the poweredmedical device to a generator or other control or measurement apparatusdesigned to provide power to the powered medical device.

The cable 35 passes into a protective element 42. Inside the protectiveelement 42, the shielding material ends and the individual wires areseparated to a greater degree. The protective element 42 may be formedof a rigid or flexible material and encompasses the wires. A hub 44abuts the protective element. The hub may be formed of a rigid material,in particular a thermoplastic or thermoset polymer material. A circuitboard 46 is positioned adjacent a forward surface of the hub 44 oppositethe protective element 42. A plurality of pins 48 protrudes from aforward surface of the circuit board 46. Embodiments of the plug furtherinclude a shield 50. A rearward portion 52 of the shield surrounds aportion of the hub 44 and the circuit board 46. A hollow forward portion54 of the shield extends forward from the circuit board and surroundsthe pins 48, protecting the pins from damage during use. Alternatively,the plug may use bars, pads, rings or other connectors that electricallyconnect the plug 40 with the cable 35.

A dividing member 56 (see FIG. 6) may extend across the inside of theshield 50 between the rearward 52 and forward 56 portions of the shield.The dividing member may have through holes 58 that accommodate pins 48extending forward from the circuit board 46. The dividing member 56 maybe integrally formed with the shield 50, for example, by injectionmolding. Alternatively, the dividing member may be formed separatelyfrom and inserted into the shield.

The plug 40 may also include a sheath 60. The sheath wraps around atleast a portion of the cable 35, protective element 42 and hub 44. Thesheath may continue forward, encompassing the circuit board 46 and atleast a portion of the shield 50. In this manner, the circuit board 46is encapsulated within the plug 40 and is only accessible by cuttingapart or otherwise destroying one or more elements of the plug.

FIG. 5 shows an alternative embodiment of a plug 140 that does not makeuse of a hub. A circuit board (not shown) is placed adjacent a rearwardend of a shield 150. A protective element 142 extends around the circuitboard and over a rearward portion 152 of the shield. A sheath 160encompasses the protective element 142.

FIG. 4 shows an embodiment of a circuit board 46 as used in the plug 40.The figure illustrates the rearward side of the circuit board.Individual wires 50 a, 50 b, 50 c connect to rearward ends 47 a, 47 b,47 c of pins 48 respectively. The pins 48 extend forwardly through thecircuit board and out into the hollow forward portion of the shield 54so that the pins can be used to engage the generator. The illustrativeembodiment of FIG. 4 includes first and second resistors 62, 64 mountedto the circuit board 46. When the powered medical device, which may bereferred to as a “wand,” is connected to the generator, these resistorsserve to identify the wand type and power limits for the generator.

The circuit board also includes a fuse 66 that bridges one of theresistors 62. When the wand is used in conjunction with a generator,this fuse-bridged resistor 62 is checked. If the fuse 66 is intact, thegenerator sends a power pulse to blow the fuse. Control circuitry in thegenerator then allows use of the wand for a limited period of time.During this period, the wand can be disconnected and reconnected withouterror on the generator. In a further embodiment, another wand of thesame model may be hooked up to the generator and used as the originalone during the limited time period. If, at any point within the limitedtime period, the generator is switched off or loses power, the wand willno longer function. If the fuse is detected as blown, the generator maydisplay an error code and prevent use of the wand.

Accordingly, the fuse 66 may be blown and the usage time of the wand maybe limited to the designated period of time. However, it is possiblethat the usage time may be unintentionally reduced below the designatedperiod of time if the generator is turned off, or if the fuse isunintentionally blown or damage. In either event, there is no way toaccess the fuse in order to repair or refurbish the fuse withoutdestroying the plug.

In accordance with embodiments of the invention, as illustrated in FIGS.7-8, a supplemental circuit board 70 is provided. An embodiment of thesupplemental circuit board 70 has a periphery 72 that generally matchesthe geometry of the inside edge 74 of the forward part of the shield 54.The supplemental circuit board 70 also includes one or more cutoutportions 76. These cutouts allow for removal of the circuit board aswill be discussed below. The supplemental circuit board carries a fuse78 and includes holes 80 in the circuit board that allow the pins 48 topass through. The supplemental circuit board is inserted into theforward portion 54 of the shield 50 such that it sits at the base of thepins 48, adjacent to the dividing member 56 of the shield.

The holes 82 a, 82 b of the supplemental circuit board 70 thatcorrespond to the pins that are connected by the fuse 66 on the circuitboard 46 are connected via the fuse 78 on the supplemental circuitboard. These holes 82 a, 82 b are sized such that they are biased tocontact the pins with a friction fit and provide an electrical contactbetween the fuse 78 and the pins. Alternatively, these pins could besoldered to contact patches formed on the circuit board, soldered toother elements of the circuit board, adhered with a conductive adhesive,or connected by other means known to those of skill in the art.

The supplemental circuit board 70 is placed into the open end of theshield 54 and is pressed into position against the dividing member 56using an installation tool 84, as illustrated in FIG. 10. Theinstallation tool 84 has a plunger end 86 that includes holes 88 thatcorrespond with the pins 48 of the plug 40. The geometry of periphery ofthe plunger end matches the inside geometry of the plug shield open end54. During repair or refurbishment of a powered medical device or wand,the supplemental circuit board 70 is placed on the top surface 90 of theplunger end 86 of the installation tool 84. The supplemental circuitboard is shaped such that it only fits on the insertion tool in oneorientation.

The supplemental circuit board is held in place on the insertion tooltop surface by vacuum. The installation tool 84, with the supplementalcircuit board 70 held on the top surface, is inserted into the plug. Thecontact force between pins 48 and one or more holes 80, 82 a, 82 b inthe supplemental circuit board holds the supplemental circuit board inplace within the plug and the installation tool is removed, leaving thesupplemental circuit board positioned in the open end of the plugagainst the base of pins 48. The fuse 78 of the supplemental circuitboard is functionally equivalent to the fuse 66 of the circuit board 46.This means that the fuse 78 functions in a sufficiently similar mannersuch that the powered medical device is capable of functioning with thefuse 78 used in place of the fuse 66. In this manner, a fuse that wasburned or otherwise damaged as part of the time limiting function of thepowered medical device may be replaced without the need to replace theentire plug or damage the integrity of the plug by destroying a plugcomponent to gain access to the fuse.

In embodiments of the invention, the supplemental circuit board 70 maybe removed and replaced with a second supplemental circuit board so thatthe wand may be repaired or refurbished more than once. The supplementalcircuit board includes cutout sections 76 along a periphery 72 of theboard. These cutouts 76 extend at least some distance into the surfaceof the board 70. As shown in FIG. 9, a removal tool is provided. Theremoval tool 94 includes a forward section 96 that is smaller indiameter than the inside of the forward portion of the shield 54. Prongs98 extend from a top surface 104 of the removal tool. The prongs consistof a base section 106 that extends upward from the top surface of theremoval tool and an engagement section 108 that extends laterally fromthe base section.

To remove a supplemental circuit board 70 from a plug 40, the removaltool is inserted into the open end 54 of the plug such that the prongs104 align with the cutouts 76 in the circuit board. The removal tool isthen twisted such that the engagement portion 108 of the prongs 104slides beneath a bottom surface of the circuit board 70 as shown in FIG.11. The removal tool may then be pulled away from the plug, therebyremoving the supplemental circuit board. The removal tool 96 may includea hollow interior portion 110 that surrounds the pins 48 and allows theremoval tool to be inserted and rotate without interfering with thepins. In alternative embodiments, the supplemental circuit board may besufficiently thin to allow multiple supplemental circuit boards to beinstalled one on top of the other such that it would not be necessary toremove a previous supplemental circuit board in order to repair orrefurbish the wand more than once.

In an alternative embodiment, as illustrated in FIG. 8, the supplementalcircuit board 70 may have two connected fuses (not shown). The firstfuse is connected with the relevant pins 48 as discussed with respect toFIG. 7. The second fuse is connected between the pins with a shortingpad 75 placed in series with the fuse. In this manner, the supplementalcircuit board may be installed and used with the wand a first time. Whenthe first fuse has been blown, the supplemental circuit board may beused a second time by connecting the elements of the shorting pad usingconductive ink or other appropriate means to bridge the elements therebyconnecting the second fuse between the pins.

In further embodiments of the invention, the circuit board of the plug40 may include non-volatile memory that stores one or more parametersrelating to the wand type or function. For example, the non-volatilememory may include information that is provided to the generator inorder to properly control the wand. The non-volatile memory may alsoinclude information indicating wand activation time and/or usage time.In this manner, the generator may determine how long the wand has beenused and limit use of the wand to a certain period of time. However, asdiscussed above, the wand may not be repaired or refurbished withoutdestroying the plug.

For example, FIG. 12 illustrates a circuit board 246 through which pins248 extend. A flip chip style integrated circuit 266 is connected to thecircuit board. The chip is connected between pins 248 such thatinformation, including time of use information, stored on the chip 266may be read by the control circuitry of the generator. FIG. 13illustrates a further embodiment in which a Joint Electron DeviceEngineering Council, Transistor Outline Package, Case Style 92 (“TO-92”)style semiconductor package is used to provide the non-volatile memory.The TO-92 package 366 is attached by pins 249 soldered or otherwiseadhered to a rearward surface of the circuit board 346. The TO-92package is electrically connected with pins 348 that extend from aforward surface of the circuit board in order to connect with agenerator. As with the flip chip (266) described with respect to FIG.12, the TO-92 package 366 is used to store information, including timeof use information, so that it may be read by the control circuitry ofthe generator.

In accordance with embodiments of the invention, as illustrated in FIG.14, a supplemental circuit board 270 is provided. The supplementalcircuit board 270 has a periphery 272 that generally matches thegeometry of the inside edge 74 of the forward part of the shield 54. Thesupplemental circuit board 270 also includes one or more cutout portions276. These cutouts allow for removal of the circuit board as will bediscussed below. The supplemental circuit board carries non-volatilememory, which may be a flip chip 278 or other appropriate packaging fornon-volatile memory. The supplemental circuit board also includes holes280 in the circuit board that allow the pins 48 to pass through. Thesupplemental circuit board is inserted into the forward portion 54 ofthe shield 50 such that it sits at the base of the pins 48, adjacent tothe dividing member 56 of the shield.

The holes 282 a, 282 b of the supplemental circuit board 270 thatcorrespond to the pins that are connected by the semiconductor package266, 366 on the circuit board 246, 346 are connected via the flip chip278 on the supplemental circuit board. These holes 282 a, 282 b aresized such that they are biased to contact the pins with a friction fitand provide an electrical connection between the flip chip 278 and thepins. Alternatively, these pins could be soldered to contact patchesformed on the circuit board.

The supplemental circuit board 278 is placed into the open end of theshield 54 and is pressed into position against the dividing member 56using an installation tool 284, as illustrated in FIG. 15. Theinstallation tool 284 has a plunger end 286 that includes holes 288 thatcorrespond with the pins (248, 248) of the plug (40). The geometry ofperiphery of the plunger end matches the inside geometry of the plugshield open end (54). During repair or refurbishment of a poweredmedical device or wand, the supplemental circuit board 270 is placed onthe top surface 290 of the plunger end 286 of the installation tool 284.The top surface of the installation tool may include a recessed portionthat corresponds to the shape of the supplemental circuit board suchthat the circuit board fits on the installation tool in one orientation.

In embodiments of the invention, the supplemental circuit board 270 maybe removed and replaced with a second supplemental circuit board so thatthe wand may be repaired or refurbished more than once. The supplementalcircuit board includes cutout sections 276 along a periphery 272 of theboard. These cutouts 276 extend at least some distance into the surfaceof the board 270. As shown in FIG. 16, a removal tool is provided. Theremoval tool 294 includes a forward section 296 that is smaller indiameter than the inside of the forward portion of the shield (54).Prongs 298 extend from a top surface 304 of the removal tool. The prongsconsist of a base section 306 that extends upward from the top surfaceof the removal tool and an engagement section or finger 308 that extendslaterally from the base section.

To remove a supplemental circuit board 270 from a plug (40), the removaltool is inserted into the open end 54 of the plug such that the prongs304 align with the cutouts 276 in the circuit board. The removal tool isthen twisted such that the engagement portion 308 of the prongs 304slides beneath a bottom surface of the circuit board 270 as shown inFIG. 16. The removal tool may then be pulled away from the plug, therebyremoving the supplemental circuit board. The removal tool 296 mayinclude a hollow interior portion 310 that surrounds the pins (248, 348)and allows the removal tool to be inserted and rotate withoutinterfering with the pins.

Programming and installing the supplemental circuit board 270 with theflip chip 278 such that the memory of the flip chip can be usedappropriately and contains the appropriate information, including timeof use information requires a number of steps. FIG. 17 shows a flowchart of the steps for refurbishing the wand a first time. First,information included on the memory contained within the plug is read 500from the plug memory into an external device such as a computer or othercontroller where the data is stored in non-volatile memory. Next, avoltage pulse is applied to the memory device within the plug to burnout or destroy the functionality of the memory device 502. In thefollowing step 504, the supplemental circuit board is installed in theplug. Next, the information recovered from the plug memory istransferred to the memory device of the supplemental circuit board 506.

In an alternative embodiment, the information may be transferred to thememory device of the supplemental circuit board prior to installation ofthe supplemental circuit board in the plug. In a further alternative,the necessary information for each model of medical device could beobtained at a prior time and stored in a database. The information couldthen be retrieved from the database for transfer to the memory device ofthe supplemental circuit board as needed. However, the informationregarding time of use is not transferred to the memory of thesupplemental circuit board, only information required by the generatoras contained in a brand new device is burned into the chip. Followingthis step, the information transferred to the supplemental circuit boardis verified 508 and, finally, all other functions of the supplementalcircuit board and wand are tested 510. Other refurbishment or repairoperations may be conducted on the wand or other powered medical devicein order to prepare it for use.

FIG. 18 shows a flow chart of the steps for refurbishing the wand asecond or subsequent time, after a supplemental circuit board hasalready been installed. First, the data included on the memory containedwithin the previously installed supplemental circuit board is read 600from the circuit board memory into an external device such as a computeror other controller where the data is stored in non-volatile memory.Next, the previous supplemental circuit board is removed from the plug602. In the following step 604, the subsequent supplemental circuitboard is installed in the plug. Next, the information recovered from theprevious supplemental circuit board memory is transferred to the memorydevice of the subsequent supplemental circuit board 606. However, theinformation regarding time of use is not transferred to the memory ofthe subsequent supplemental circuit board, only information required bythe generator as contained in a brand new device is burned into thechip. Following this step, the information transferred to the subsequentsupplemental circuit board is verified 508 and, finally, all otherfunctions of the subsequent supplemental circuit board and wand aretested 510. Again, other refurbishment or repair operations may beconducted on the wand or other powered medical device in order toprepare it for use. As discussed with regard to a first refurbishment,the information may be transferred to the memory device of thesupplemental circuit board prior to installation of the supplementalcircuit board in the plug, and the necessary information for each modelof medical device could be obtained at a prior time, stored in adatabase, and retrieved from the database for transfer to the memorydevice of the supplemental circuit board as needed.

The flip chip 278 of the supplemental circuit board is functionallyequivalent to the memory device 266, 366 of the circuit board 246, 346.This means that the flip chip 278 functions in a sufficiently similarmanner such that the powered medical device is capable of functioningwith the flip chip 278 used in place of the memory device 266, 366. Inthis manner, a memory device that is disabled, expended, consumed,damaged or otherwise rendered inoperable as part of the time limitingfunction of the powered medical device may be replaced without the needto replace the entire plug or damage the integrity of the plug bydestroying a plug component to gain access to the fuse.

Various embodiments discussed above reference a flip chip. However, oneof ordinary skill in the art would recognize that any appropriate memorydevice capable of meeting the size constraints of the plug could beused.

In addition, various embodiments discuss the use of a supplementalcircuit board. As used herein, supplemental circuit board is not limitedto any particular structure or composition. Rather, this term mayinclude any structure that provides for electrical connection of one ormore electronic components to the pins of a plug or other accessibleelectrical elements of a powered medical device. The supplementalcircuit board may be any size or shape that allows it to bridge betweenpins of the plug, and it need not match the geometry of the plug. Forexample, in certain embodiments, the supplemental circuit board maycomprise a printed circuit board with conductive tracks laminated onto anon-conductive substrate to which electronic components are attached. Inother embodiments, the supplemental circuit board may comprise a moldedstructure in which electronic components are embedded.

In further embodiments, the supplemental circuit board need not be acircuit board in the sense of requiring a non-conductive substrate withcomponents mounted on its surface. The supplemental circuit board mayhave any configuration that comprises one or more electronic componentscoupled with means to connect the electronic component to pins or otherconnectors of the plug. For example, the supplemental circuit board maycomprise a memory chip (such as an EPROM or EEPROM), a fuse or anotherelectronic component that is coupled with ring connections that slideonto pins of the plug.

The powered medical devices and methods have been described as havingcertain exemplary features or steps. However, it is contemplated thatthe present invention may include any compatible features or steps shownor describe with respect to other embodiments disclosed herein or otherfeatures as would be understood by one of ordinary skill in the art.

We claim:
 1. A method for refurbishing a limited use medical devicecomprising the steps of: reading a memory of a limited use medicaldevice; transferring data from the limited use medical device to anexternal device for storage and later retrieval; applying an electricalsignal to the limited use medical device wherein a functionality of thememory of the limited use medical device is disabled; installing asupplemental circuit board into the limited use medical device;transferring the stored data from the external device to a memory of thesupplemental circuit board; verifying the transferred data; and testinga functionality of the limited use medical device with the supplementalcircuit board installed.